Hot Standby Router Protocol (HSRP) is the Cisco proprietary implementation of FHRP.

A

The Cisco proprietary implementation of FHRP (First Hop Redundancy Protocol) is the Hot Standby Router Protocol (HSRP), which allows a group of routers to share a virtual IP address and MAC address to provide redundancy for hosts on a LAN.

When HSRP is configured on a network, one router is elected as the active router and another as the standby router. The active router is responsible for forwarding packets sent to the virtual IP address, while the standby router monitors the active router and takes over if the active router fails or becomes unavailable.

HSRP uses a virtual MAC address that is shared between the active and standby routers, allowing hosts on the LAN to continue sending traffic to the same MAC address even if the active router fails. This ensures minimal disruption to network traffic in the event of a router failure.

Other FHRP implementations include Virtual Router Redundancy Protocol (VRRP), which is an open standard protocol that provides similar functionality to HSRP, and Gateway Load Balancing Protocol (GLBP), which provides load balancing in addition to redundancy. CARP (Common Address Redundancy Protocol) is a similar protocol developed by the OpenBSD project. However, HSRP is the Cisco proprietary implementation of FHRP.